The invention relates to an orthodontic device in the form of a bracket with wings disposed on a base plate.
German patent No. 27 16 341 describes a bracket of this type consisting of an integral part which is parted off from a wire strand preformed by form milling. Depending on the design of the brackets, finish-milling work is still necessary on the individual bracket after parting off from the wire strand, for example when the bracket slot is to be inclined.
After being manufactured, brackets of this type are provided at the underside of their base plate with a separate adhesive support or adhesive base which may consist of a layer of metal foil and a layer of metal gauze welded to the layer of metal foil. The layer of metal foil may, however, be welded directly to the underside of the base plate of the bracket.
Brackets of this type are extremely expensive, can only be produced in large numbers of uniform brackets in order to limit the production costs and, particularly if the bracket slot is inclined, have unequal thicknesses of material at each side of the bracket slot and hence regions of very different strength. The preprofiled wire strands as starting material for production lead to a severe limitation in shape while the separate adhesive support or adhesive base involves considerable additional costs and causes a spacing of the bracket from the tooth surface to which the bracket is to be stuck which is increased by the thickness of the adhesive base.
Brackets constructed in the form of integral parts are further known which are formed from an individually preformed cast blank for each bracket. The final shaping of such cast brackets, which again have to be provided with a separate adhesive support or adhesive base at the underside of their base plate, is effected by finish-milling the cast blanks introduced into pallets in groups. Such brackets are also extremely expensive because of their manufacture and suffer from the further disadvantages already listed above. Here, too, the casting mould predetermines a basic shape for the blank which only leaves strictly limited possibilities of modification during the production of the finished shape. Therefore, about 60 different casting moulds are needed in order to produce those blanks from which more than 100 different shapes of brackets are then completed.